Hematopoietic stem progenitor cells (HSPCs) are normally present in very small numbers in the circulating blood. However, in response to stress or injury, HSPCs are primed to migrate out of their niche into the peripheral blood. HSPCs have been developed as an alternative to bone marrow harvest for transplant. Because they exhibit faster engraftment and reduced risk of posttransplant infection, mobilized HSPCs are now more commonly used as stem cell sources.
Uridine diphosphate-glucose (“UDP-glucose”) is a nucleotide sugar which is released into extracellular fluids in response to various stressors (Lazarowski et “Release of cellular UDP-glucose as a potential extracellular signaling molecule,” Mol Pharmacol 63, 1190-1197, 2003). UDP is a potent agonist of the human P2Y14 receptor (Carter et al., “Quantification of Gi-mediated inhibition of adenylyl cyclase activity reveals that UDP is a potent agonist of the human P2Y14 receptor,” Mol. Pharmacol. 76(6):1341-8, 2009) and has been reported to be associated with a number of physiologic effects, including inotropic effects in cardiac myocytes mediated by P2Y6 receptors via an IP3-dependent pathway (Wihlborg et al., “Positive inotropic effects by uridine triphosphate (UTP) and uridine diphosphate (UDP) via P2Y2 and P2Y6 receptors on cardiomyocytes and release of UTP in man during myocardial infarction,” Circ. Res. 98(7):970-6, 2006).